What Causes High Idle Speed During Cold Starts in Winter?
1 Answers
Cold start idle speed suddenly increasing is a normal phenomenon, designed to help the engine quickly reach its optimal operating temperature. Below are the reasons for the sudden rise in idle speed during cold starts:1. During cold conditions, the coordination between various engine components is not at its best. The optimal operating temperature for engines after prolonged use is between 80-110 degrees Celsius. Therefore, during the design and manufacturing of the engine, each component is optimized to achieve the best coordination at this temperature. Increasing the idle speed helps the engine reach its working temperature faster.2. In cold conditions, the intake air temperature is low, leading to poor fuel atomization. Some fuel sprayed from the injectors does not atomize properly and instead adheres to the intake manifold, which can lead to carbon buildup. This also makes it difficult to control the concentration of the air-fuel mixture entering the engine. To address this issue, the best solution is to quickly raise the engine coolant temperature, hence increasing the idle speed during cold starts is the most effective method.3. This phenomenon varies depending on the climate and temperature. For example, in northern regions or extremely cold environments, the increase in idle speed after starting the car is more significant and lasts longer. Conversely, in higher ambient temperatures, the fluctuation in idle speed after engine startup is minimal or even unnoticeable.
